The effects of chestnut orchard microclimate on burr development

•Characterization of seasonal, daily and hourly chestnut burr growth.•Burr showed higher growth rate in the last part of the season (September-October).•Daily burr development was characterized by night-swelling and daily-shrinkage.•Burr daily net growth was phenologically dependent on environmental parameters.•Atmosphere humidity was the main microclimate driver of burr daily growth.